<!DOCTYPE html>

<head>
    <meta charset="UTF-8">
    <style>
        div {
            width: 100px;
            height: 100px;
            background-color: chocolate;
        }
    </style>
    <script src="../jQuery-3.6.3.min.js"> </script>
    <script>
        $(function () {
            $("#a1").click(function () {
                $("div").animate({ "width": "200px" }, 2000).delay(2000)
                    .animate({ "height": "270px" }, 1000)
                    .animate({ "width": "500px" }, 3000);

            });
            $("#a2").click(function () {
                $("div").stop(true);
            })

        })
    </script>
</head>

<body>
    <input type="button" id="a1" value="开始"><br />
    <input type="button" id="a2" value="停止">
    <div>

    </div>
</body>

</html>